We'll be using CircuitPython for this project. Are you new to using CircuitPython? No worries, there is a full getting started guide here.

Adafruit suggests using the Mu editor to edit your code and have an interactive REPL in CircuitPython. You can learn about Mu and its installation in this tutorial.

There's a guide to get you up and running with CircuitPython specifically for the NeoTrellis M4. You should read it before starting to get the most recent CircuitPython build for the NeoTrellis M4 installed and running along with the required libraries.

Setting up your the NeoTrellis

To get your NeoTrellis M4 setup to run this project's code, first follow these steps:

1) Update the bootloader for NeoTrellis from the NeoTrellis M4 guide

2) Install the latest CircuitPython for NeoTrellis from the NeoTrellis M4 guide

3) Get the latest 4.0 library pack, unzip it, and drag the libraries you need over into the /lib folder on CIRCUITPY. The latest library package includes support for NeoTrellis.

For this project you will need the following libraries:

  • adafruit_trellism4.mpy
  • neopixel.mpy
  • adafruit_matrixkeypad.mpy

When the libraries and code is installed CIRCUITPY should look like:

To complete your setup, click code.py in the GitHub window heading below and save the file to your NeoTrellis CIRCUITPY drive in the main/root directory as code.py. The code will start immediately and play the game.

If the game does not play, check your NeoTrellis setup at the top of the page and ensure the three library .mpy files are in the /lib directory on the CIRCUITPY drive.

NeoTrellis M4 Express Memory Game

Adafruit invests time and resources providing this open source code.
Please support Adafruit and open source hardware by purchasing
products from Adafruit!

Written by Dave Astels for Adafruit Industries
Copyright (c) 2018 Adafruit Industries
Licensed under the MIT license.

All text above must be included in any redistribution.

# pylint: disable=stop-iteration-return

import time
import random
import adafruit_trellism4

COLORS = [0xFF0000, 0xFFFF00, 0x00FF00, 0x00FFFF, 0x0000FF, 0xFF00FF]

trellis = adafruit_trellism4.TrellisM4Express(rotation=0)
trellis.pixels.brightness = 0.1

pixel_colors = [None] * 32
found_pairs = 0
previously_pressed = set([])
first_pixel = None

key_pressed = None

def index_of(coord):
    x, y = coord
    return y * 8 + x

def wheel(pos):
    # Input a value 0 to 255 to get a color value.
    # The colours are a transition r - g - b - back to r.
    if pos < 0 or pos > 255:
        return 0, 0, 0
    if pos < 85:
        return int(255 - pos*3), int(pos*3), 0
    if pos < 170:
        pos -= 85
        return 0, int(255 - pos*3), int(pos*3)
    pos -= 170
    return int(pos * 3), 0, int(255 - (pos*3))

def cycle_sequence(seq):
    while True:
        for elem in seq:
            yield elem

def rainbow_lamp(seq):
    g = cycle_sequence(seq)
    while True:

def splash():
    rainbow = rainbow_lamp(range(0, 256, 8))
    for _ in range(64):

def assign_colors():
    unassigned = [(x, y) for x in range(8) for y in range(4)]
    while unassigned:
        first_of_pair = random.choice(unassigned)
        second_of_pair = random.choice(unassigned)
        random_color = random.choice(COLORS)
        pixel_colors[index_of(first_of_pair)] = random_color
        pixel_colors[index_of(second_of_pair)] = random_color

def handle_key(key, _found_pairs, _first_pixel):
    if key is None:
        return _found_pairs, _first_pixel
    key_color = pixel_colors[index_of(key)]
    if key_color is not None:
        trellis.pixels[key] = pixel_colors[index_of(key)]
        if _first_pixel and _first_pixel != key:
            if key_color == pixel_colors[index_of(_first_pixel)]:
                pixel_colors[index_of(_first_pixel)] = None
                pixel_colors[index_of(key)] = None
                for _ in range(5):
                    trellis.pixels[_first_pixel] = 0xFFFFFF
                    trellis.pixels[key] = 0xFFFFFF
                    trellis.pixels[_first_pixel] = 0x000000
                    trellis.pixels[key] = 0x000000
                trellis.pixels[_first_pixel] = 0x444444
                trellis.pixels[key] = 0x444444
                return _found_pairs + 1, None
                trellis.pixels[_first_pixel] = 0x000000
                trellis.pixels[key] = 0x000000
                return _found_pairs, None
            return _found_pairs, key
    return _found_pairs, None

def check_for_key(last_pressed):
    now_pressed = set(trellis.pressed_keys)
    new_presses = now_pressed - last_pressed
    if new_presses:
        return now_pressed, list(new_presses)[0]
    return now_pressed, None

demo_mode_enabled = True
while True:
    found_pairs = 0
    first_pixel = None
    remaining = [(x, y) for x in range(8) for y in range(4)]
    while found_pairs < 16:
        if demo_mode_enabled:
            previously_pressed, key_pressed = check_for_key(previously_pressed)
            if key_pressed:
                demo_mode_enabled = False
            first = random.choice(remaining)
            found_pairs, first_pixel = handle_key(first, found_pairs, first_pixel)
            previously_pressed, key_pressed = check_for_key(previously_pressed)
            if key_pressed:
                demo_mode_enabled = False
            c = pixel_colors[index_of(first)]
            match = random.choice([x for x in remaining if pixel_colors[index_of(x)] == c])
            found_pairs, first_pixel = handle_key(match, found_pairs, first_pixel)
            previously_pressed, key_pressed = check_for_key(previously_pressed)
            found_pairs, first_pixel = handle_key(key_pressed, found_pairs, first_pixel)
    if found_pairs == 16:

This guide was first published on Dec 13, 2018. It was last updated on Dec 13, 2018.

This page (Code) was last updated on Feb 18, 2021.

Text editor powered by tinymce.